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Articles 1 - 3 of 3
Full-Text Articles in Cell Biology
Pcdp1 Is A Central Apparatus Protein That Binds Ca2+-Calmodulin And Regulates Ciliary Motility, Christen G. Dipetrillo, Elizabeth F. Smith
Pcdp1 Is A Central Apparatus Protein That Binds Ca2+-Calmodulin And Regulates Ciliary Motility, Christen G. Dipetrillo, Elizabeth F. Smith
Dartmouth Scholarship
For all motile eukaryotic cilia and flagella, beating is regulated by changes in intraciliary calcium concentration. Although the mechanism for calcium regulation is not understood, numerous studies have shown that calmodulin (CaM) is a key axonemal calcium sensor. Using anti-CaM antibodies and Chlamydomonas reinhardtii axonemal extracts, we precipitated a complex that includes four polypeptides and that specifically interacts with CaM in high [Ca2+]. One of the complex members, FAP221, is an orthologue of mammalian Pcdp1 (primary ciliary dyskinesia protein 1). Both FAP221 and mammalian Pcdp1 specifically bind CaM in high [Ca2+]. Reduced expression of Pcdp1 complex …
Supervillin Slows Cell Spreading By Facilitating Myosin Ii Activation At The Cell Periphery, Norio Takizawa, Reiko Ikebe, Mitsuo Ikebe, Elizabeth J. Luna
Supervillin Slows Cell Spreading By Facilitating Myosin Ii Activation At The Cell Periphery, Norio Takizawa, Reiko Ikebe, Mitsuo Ikebe, Elizabeth J. Luna
Elizabeth J. Luna
During cell migration, myosin II modulates adhesion, cell protrusion and actin organization at the leading edge. We show that an F-actin- and membrane-associated scaffolding protein, called supervillin (SV, p205), binds directly to the subfragment 2 domains of nonmuscle myosin IIA and myosin IIB and to the N-terminus of the long form of myosin light chain kinase (L-MLCK). SV inhibits cell spreading via an MLCK- and myosin II-dependent mechanism. Overexpression of SV reduces the rate of cell spreading, and RNAi-mediated knockdown of endogenous SV increases it. Endogenous and EGFP-tagged SV colocalize with, and enhance the formation of, cortical bundles of F-actin …
Supervillin Reorganizes The Actin Cytoskeleton And Increases Invadopodial Efficiency, Jessica Lynn Crowley, Tara C. Smith, Zhiyou Fang, Norio Takizawa, Elizabeth J. Luna
Supervillin Reorganizes The Actin Cytoskeleton And Increases Invadopodial Efficiency, Jessica Lynn Crowley, Tara C. Smith, Zhiyou Fang, Norio Takizawa, Elizabeth J. Luna
Elizabeth J. Luna
Tumor cells use actin-rich protrusions called invadopodia to degrade extracellular matrix (ECM) and invade tissues; related structures, termed podosomes, are sites of dynamic ECM interaction. We show here that supervillin (SV), a peripheral membrane protein that binds F-actin and myosin II, reorganizes the actin cytoskeleton and potentiates invadopodial function. Overexpressed SV induces redistribution of lamellipodial cortactin and lamellipodin/RAPH1/PREL1 away from the cell periphery to internal sites and concomitantly increases the numbers of F-actin punctae. Most punctae are highly dynamic and colocalize with the podosome/invadopodial proteins, cortactin, Tks5, and cdc42. Cortactin binds SV sequences in vitro and contributes to the formation …